What does HackerNews think of valhalla?

Open Source Routing Engine for OpenStreetMap

Language: C++

Valhalla is an open-source routing engine, like for from traveling from point A to point B. I think Tesla uses it as the basis for their in-car navigation system. It produces routes very quickly and has a pretty robust costing model (cars can travel on different roads from bikes, bikes can travel different places than pedestrians, right turns are easier than left turns, sharp left turns are worse than slight left turns, etc). It can produce turn-by-turn instructions and gpx output. It also does map matching pretty well (converting messy GPS data to an actual snapped-to-streets path), traveling salesman solutions and a few other things.

(https://github.com/valhalla/valhalla)

Thanks for mentioning this. Also keep in mind that mapzen its isochrone API:

https://github.com/valhalla/valhalla

as well as ours is open source:

https://github.com/graphhopper/graphhopper/pull/1237